Seeing this error? Network delay, wrong registered mobile, or a full SMS inbox usually cause OTP failures. Below are the common causes and the fixes that resolve it for most users.
Why this happens
- The mobile number registered on the GST portal is outdated or different from the one you expect.
- Telecom network congestion is delaying the SMS by a few minutes.
- DND (Do Not Disturb) settings or a full message inbox are blocking transactional SMS.
- You are using the wrong OTP mode — since 2FA, OTP can arrive via SMS, the Sandes app, or the NIC-GST-Shield app.
How to fix it
Wait 2–3 minutes
Transactional OTPs can be delayed during peak hours. Wait a couple of minutes before requesting a new one.
Check the registered mobile
Confirm the OTP is going to the mobile linked to your GSTIN, not a personal number. Update it on the GST portal if needed.
Try an alternate 2FA mode
Install the Sandes or NIC-GST-Shield app and generate the OTP there — it works even on weak networks.
Clear the SMS inbox
A full inbox silently drops new messages. Delete old SMS and request the OTP again.
Use 'Resend OTP'
Click resend rather than reloading the page, which can invalidate the first OTP.
Still stuck? Compare with other issues in the full error guide, or review the login guide.